反应详情

A mixture of 44 g of 1-(1-benzyl-4-piperidyl)-3-(4-methoxy-phenyl)-imidazolidin-2-one, 320 ml of methanol, 130 ml of water and 12 g of a conc. aqueous solution of hydrochloric acid, with the addition of 10 g of a palladium on charcoal catalyst, is hydrogenated at 30° to 40° C and under reduced pressure until 1 molar equivalent of hydrogen has been taken up. Thereafter the catalyst is removed by filtration and the filtrate is concentrated under reduced pressure. The residue is treated with toluene and recrystallised from a mixture of isopropyl alcohol and diethyl ether to yield the 1-(4-methoxyphenyl)3-(4-piperidyl)-2-imidazolidinone with a melting point of 140° C.

1. customThereafter the catalyst is removed by filtration
2. concentrationthe filtrate is concentrated under reduced pressure
3. additionThe residue is treated with toluene
4. customrecrystallised from a mixture of isopropyl alcohol and diethyl ether